Method for adjusting a tilt-furnace



Feb. 10, 1970 smesnoau SHINADO'I 3 METHOD FOR ADJUSTING A TILT-FURNACE Original FilecJune. 2, 1966 2 Sheets-Sheet 1 6.2 Y FlG.l

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United States Patent 3,494,602 METHOD FOR ADJUSTING A TILT-FURNACE Shigenobu Shindo, Kawasaki-shi, Japan, assignor to Nippon Kokan Kabushiki Kaisha, Tokyo, Japan, a corporation of Japan Original application June 2, 1966, Ser. No. 554,723. Divided and this application July 2, 1968, Ser. No. 741,-

Int. Cl. F27d 3/14; F27b 3/06, 14/02 US. Cl. 26352 5 Claims ABSTRACT OF THE DISCLOSURE A method for adjusting a tilt-furnace. According to the method, the tilt-furnace is swung between given end positions. While maintained at at least one of these end positions, at one end of its swinging movements, the angular positions of furnace supporting rollers are adjusted. Thus, during the subsequent swinging of the furnace in an opposite direction the adjusted rollers, which support the furnace for tilting movement, will displace the furnace in a given direction so as to adjust the position thereof.

Cross-reference to related application This application is a division of copending US. patent application, Ser. No. 554,723, filed June 2, 1966, entitled Method and Apparatus for Adjusting a Tilt-Furnace.

Background of the invention The present invention relates to furnaces.

More particularly, the present invention relates to tiltfurnaces of the type which have a hollow generally horizontally extending furnace body which is capable of tilting about a substantially horizontal axis so that when tilted in one direction slag can be poured out of the furnace body while when tilted in an opposite direction molten pig iron or the like can be poured from the other side of the furnace body.

It is conventional to support furnace bodies of this type with rocker assemblies which include rows of rollers which roll along runners during tilting of the furnace body. The positions between the rollers and the runners with which they have rolling contact changes unavoidably during operation as a result of various factors, among which may be manufacturing errors or errors in the installation of the runners, and in addition the effects of wear and expansion and contraction due to temperature changes will result in unavoidable departures from the ideal position of the furnace and the ideal cooperation between the rollers and runners.

These unavoidable deviations of the position of the furnace body from its ideal position results in several disadvantages such as a roughness in the furnace operation, improper pouring of the molten metal, on the one hand, and the slag, on the other hand, and in addition once excessive wear has started as a result of improper positioning of the furnace the rate of wear accelerates and the life of the entire furnace is considerably shortened.

Although the presence of these faults are well known, no particular measures have been taken up to the present time to correct them, because of the great difficulties encountered in solving this problem. Thus, furnaces of this type when adapted to handle a load of 2000 tons, for example, must in and of themselves weigh on the order of 700 tons, so that the loads with which the rollers are stressed are so tremendous that the furnace is operated without any particular steps being taken to correct faults of the above type. As a result the full effective use of a furnace cannot be achieved, and in those cases where the nature of the operations is such that any accidents 3,494,602 Patented Feb. 10, 1970 due to mechanical damaging of furnace parts are absolutely impermissible, adjustments are made only with the utmost ditficulty.

Summary of the invention It is therefore a primary object of the present invention to provide for a tilt-furnace of this type a method which will enable the position of the furnace to be corrected, so as to eliminate the above drawbacks.

In addition, it is an object of the present invention to provide a method which can bring about the desired corrections without the addition of any special devices to the furnace for this particular purpose.

Furthermore, it is an object of the invention to provide a method which takes advantage of the tilting movements of the furnace body itself to bring about the required adjustment of the location of the furnace body.

Thus, it is an object of the present invention to provide a method which is capable of adjusting a furnace body of the above type in an extremely convenient manner with the use of an exceedingly simple structure.

In accordance with the invention at least some of the rollers which support the furnace body for tilting movement are operatively connected with a plurality of bearing means which are capable of adjusting the positions of the roller axes so that by setting the roller axes at preselected angles it is possible through the adjusted rollers to provide during the tilting of the furnace com ponents of force which will shift the furnace body to correct its position.

,Brief description of drawings The invention is illustrated by way of example in the accompanying drawings which form part of this application and in which:

FIG. 1 is a schematic transverse sectional elevation of a tilt-furnace, FIG. 1 showing the structure for tilting the furnace as well as for supporting the furnace for tilting movement;

FIG. 2 is a side view of the structure of FIG. 1;

FIG. 3 shows in fragmentary end and longitudinal sectional elevations conventional bearing structure for a roller;

FIG. 4 shows in fragmentary end and longitudinal sections one possible embodiment of a structure according to the present invention;

FIGS. SA-S'C are, respectively, schematic illustrations showing positions which may be given to the rollers in accordance with the invention;

FIG. 6 shows the furnace in a transverse section similar to FIG. 1 at one end position of tilting movement;

FIG. 7 shows the furnace of FIG. 6 at an opposite end position of tilting movement; and

FIGS. 8A-8C, respectively, schematically illustrate various possibilities in the adjustments which can be achieved with the present invention.

Description of preferred embodiments Referring to FIGS. 1 and 2, the tilt-furnace illustrated therein includes a furnace body 1 provided with a discharge spout 11 through which molten pig iron can be poured from one side of the furnace body 1, this furnace body 1 having at its opposite side a slap discharge spout 12.

The furnace body 1 is supported for tilting movement by a rocker assembly which includes, in the illustrated example, a pair of upper runners 2 which are respectively fixed to the underside of the furnace body 1 and which have downwardly directed curved runner surfaces each of which extends along a circle whose axis coincides with the turning axis of the furnace. The rocker assembly includes beside the upper pair of runners 2 a lower pair of runners which may be stationary and which have upwardly directed runner surfaces of the same curvature as the downwardly directed surfaces of the runners 2 and spaced therefrom to define therewith elongated arcuate gaps which extend along circles whose centers are in the turning axis of the furnace body. Situated in each gap is a row of mutually spaced rollers 3 in rolling engagement with the curved runner surfaces which define the gap. In order to maintain the rollers 3 of each row at a given spacing with respect to each other, the rollers are each provided at their ends with journals received in bearings carried by a pair of side bars 4 respectively situated along opposite sides of each row of rollers 3.

In order to tilt the furnace a rack 6 is pivotally connected at one end by a pivot pin 9 to a projecting lug 8 which is fixed to and projects from the furnace body in the manner shown in dot-dash lines in FIG. 1, and a pinion 7 meshes with the rack 6 and is driven by a furnace-tilting motor through a suitable reduction gearing or the like, so that in this way the fumace body can be tilted in opposed directions to selectively provide discharge of molten metal or slag.

Referring now to FIG. 3, which shows a conventional bearing structure for a journal at an end of a roller 3, it will be seen that each roller 3 has at each of its ends a journal 3 received in a bearing carried by one of the side bars 4. As a result the rollers 3 are not only capable of rotating with respect to the side bars 4, but these side bars in addition act to maintain the required spacing between the rollers While they roll along the runners 2 and 5. With a conventional arrangement as shown in FIG. 3 the roller axes will at all time be maintained in given positions which ideally should extend parallel to the tilting axis of the furnace but which by reason of the above factors deviate in practice considerably from this ideal, giving rise to the above-discussed faults.

With a structuree of this type it is possible to tilt the furnace between the positions shown in FIGS. 6 and 7, one of these positions being that shown in FIG. 7 Where the furnace is tilted through an angle of approximately 50 to a maximum tilted position providing for discharge of molten metal through the spout 11, while in the opposite direction of tilt it is possible to bring the furnace to the position shown in FIG. 6 where it is tilted through an angle of about to bring about discharge of a slag from the spout 12. As is apparent from FIGS. 6 and 7, the length'of the runners 5 is such that in each of the end positions several rollers at the end of each row of rollers project beyond the runners 5 and are in a floating state, in that they are unsupported at their undersides. Thus, in the end position of FIG. 6 there are three rollers 3 at the rightend of each row which are situated beyond the lower runners 5, while in the end position of FIG. 7 there are five rollers 3 at the other end of each row of rollers situated beyond the runner 5.

In accordance with the invention advantage is taken of the floating state of these rollers at the ends of the rows to adjust at least these floating rollers to bring about required repositioning of the furnace body 1 during successive tilting movements thereof. For this purpose the invention includes for each adjustable roller 3, at least, a pair of bearing means cooperating with its journals, and one of these bearing means is shown in FIG. 4. Thus, referring to FIG. 4, it will be seen that the journal 3' is received in a bearing means 10 carried by the side bar 4 and having an outer bearing member provided with an inner bearing surface which forms part of a sphere. The journal 3' itself is surrounded and supported for rotary movement by a bearing member 13 which has an exterior bearing surface 13' forming part of the same sphere as that of the inner surface of the outer bearing member and slidably engaging the latter inner surface. With this construction it is possible, particularly when a given roller is in the floating state, to shift the inner bearing member with respect to the outer bearing member, although to a relatively small degree, so as to provide a change in the angular position of the adjusted roller 3. The extent of adjustment of the roller axis is on the order, for example, of 12.

Thus, referring to FIGS. 5A5C, it is possible with the structure of the invention to provide an arrangement of rollers, for one or both rows, as shown at arrangement of FIG. 5A in which all of the rollers have parallel axes. In addition, however, it is possible to provide an adjustment as shown in FIG. 5B according to which some rollers remain parallel to the furnace axis while others are inclined with respect thereto, and it is even possible to provide an arrangement as shown in FIG. 5C where successive rollers have opposed angular directions. Thus, a considerable range of possible combinations of adjustments of the rollers is possible with the invention.

As has already been pointed out above, the faulty positioning of the furnace body has been found to be the result of dimensional errors in the manufacture of the parts such as the rollers, the runners, the furnace body, etc., as well as departures from ideally adjusted positions due to wearing of the parts, due to sliding rather than rolling contact therebetween, as well as to unbalance forces, errors in installation, and displacements resulting from repeated expansion and contraction brought about by temperature changes. Lack of uniformity in temperature variations throughout the furnace body will also contribute to faulty positioning of the furnace, and once an error occurs it will shift from one part to another part of the furnace, although gradually, during the repetitious tilting movements of the furnace.

The result is that flanges at the ends of the rollers may rub undesirably along the runners or the rack 6 will undesirably strike laterally against or rub against other elements.

In order to correct the above drawbacks the furnace body is tilted, in accordance with the method of the invention, to one end of the end positions shown in FIGS. 6 and 7 either when the furnace is empty or when the quantity of molten material therein is relatively small, so that under these conditions the floating state of the rollers situated beyond the lower runners is enhanced. These floating rollers are adjusted in the manner described above, for example by localized tapping forces applied against selected areas of the inner bearing members 13 to tilt them with respect to the outer bearing members and thus provide a slight change in the direction in which the axis of the adjusted roller extends. Thus, for example, referring to FIG. 8A, it will be seen that the group I of the two rows of rollers 3 are angularly adjusted in the manner indicated. When the rows of rollers are advanced in the direction of the arrow (a) shown in FIG. 8A, they will tend to roll in the direction of the arrow (b) shown in FIG. 8A, with the result that there is a component of force acting in the direction of the arrow (c) tending to displace the tilted rollers to the left, as viewed in FIG. 8A. If only a relatively small number of rollers have their positions adjusted in this way it may well be that the remaining rollers will dominate and the adjustment will be extremely small, if any. On the other hand, if a relatively large number of rollers is adjusted, they will produce a shift in the direction of the arrow (c). During tilting of the furnace body in the opposite direction the rollers will automatically assume their initial positions where their axes extend parallel to the furnace axis.

Referring to FIG. 8B, when the rows of rollers illustrated therein are displaced in the direction of the arrow (a) of FIG. 8B, with groups I and III adjusted as illustrated, these rollers will tend to roll in the direction of the arrow (b) of FIG. 8B, thus providing a component of force acting in the direction of the arrow (d) which will tend to displace the furnace in the opposite direction from that shown in FIG. 8A, and the extent of adjustment of the furnace body will be the difference between the ad justment derived from the group of rollers I and that derived from the group of rollers III. While the extent of angular adjustment of the rollers is limited so that it is in the range of 1-20", as pointed out above, repeated tilting movements as described above will make it possible to restore the furnace to its correct position.

It is also possible to provide adjustments as indicated in FIG. 80, according to which only rollers of one of the rows are adjusted. In this case it will be noted that only the rollers of the right row are adjusted. Thus, the rollers of group III and the rollers of group I of the right row of FIG. 8C are successively adjusted in opposed directions, as schematically indicated. The result is that these adjusted rollers will have a braking action which will in fact displace the right row of rollers with respect to the left row of rollers, and with such an arrangement it becomes possible to correct the difference between the front and rear positions of the furnace. The adjustments are of course brought about by tilting movement of the furnace due to the frictional engagement between the adjusted rollers and the runners 2. and 5.

Of course, since it is possible with the invention to adjust the angles at which the roller axes extend, it becomes possible to correct various deviations in addition to those referred to above, by conveniently changing and selecting the numbers of rollers which are to be given a given angle and of course by selecting the particular angle of adjustment, the row in which the adjusted rollers are located, and the relative position between the load applied on the individual rollers according ot the center of gravity of the furnace and the rollers which have been adjusted to a given angle.

Therefore, in accordance with the method of the invention it becomes possible to easily correct deviations resulting from operation of the furnace, and in addition the method of the invention requires no troublesome prO- cedures such as removal of firebrick, and the like. The adjustments are brought about during the normal tilting movements of the furnace, and the required adjustment is achieved in an exceedingly simple way very easily and in an extremely short time. Moreover, inasmuch as the construction required for the invention is quite simple, all that is required being the bearing structure such as that shown in FIG. 4, the structure of the invention is exceedingly inexpensive. Therefore, it is apparent that the method of the invention is of considerable advantage to the operation of tilt-fumaces of the above type.

What is claimed is:

1. A method of adjusting the position of a tilt-furnace supported by rollers which are capable of being angularly adjusted particularly when the rollers are in a non-loaded condition when they do not support the tilt-furnace, comprising the steps of swinging the tilt-furnace between end positions thereof where at least some of said rollers are in said non-loaded condition, and while said furnace is maintained at at least one end of its swinging .movement adjusting the angular positions of rollers which are in said non-loaded condition, so that the adjusted rollers will tend during subsequent swinging of the furnace in an opposite direction to displace the furnace in a given direction different from the direction in which the furnace would have moved without adjustment of said rollers.

2. A method as recited in claim 1 and wherein at least some rollers are in a floating state unsupported at their undersides when said furnace is in the region of one end of its swinging movement, and wherein those rollers which are in a floating state are adjusted prior to subsequent swinging of the furnace back in an opposite direction.

3. The combination of claim 1 and wherein some rollers are adjusted in one direction and other rollers are adjusted in an opposite direction.

4. A method as recited in claim 1 and wherein those rollers which are adjusted are all adjusted in the same direction.

5. A method of adjusting a tilt-furnace comprising the steps of angularly adjusting the positions of the rollers of only one of two rows of rollers which support the furnace for tilting movement with the adjusted rollers alternately adjusted in opposed angular directions for braking the movement of said row of rollers so that the latter will become offset with respect to the other row of rollers while providing a furnace adjustment.

References Cited UNITED STATES PATENTS 481,885 8/1892 Aiken et al 26333 JOHN J. CAMBY, Primary Examiner US. Cl. X.R. 26333; 26636 

